Keir Starmer is expected to announce his resignation as Prime Minister on Monday, with Andy Burnham emerging as the frontrunner among Labour MPs. The Business Secretary confirmed Starmer spent the weekend “making time to reflect on the political realities” he faces. A former Cabinet Secretary warned on the BBC this morning that leadership transitions are “enormously disruptive.” Markets will open Monday morning without a clear sense of who leads the government or when a successor is confirmed, which matters for gilt positioning and any near-term fiscal signalling.

The Strait of Hormuz situation is worth watching closely. Iran claimed to have closed the waterway in response to Israeli attacks in Lebanon; the US disputed that characterisation. JD Vance has arrived in Switzerland for talks aimed at a permanent end to the US-Iran-Israel conflict, with initial focus on the Lebanese front. The preliminary ceasefire signed at Versailles last week is being widely described as a climb-down for Washington. Rahm Emanuel, positioning himself for a Democratic presidential run, called it an “American national security mess” and said Trump “got schooled” by Iran. Energy markets will be sensitive to any deterioration in the Hormuz situation even if the closure claim proves overstated.

Ukraine-Russia: the FT reports that Ukrainian drone innovations are cutting into Russia’s manpower advantage, with Moscow’s war machine described as sputtering. Nothing here that changes the week’s positioning materially, but it reinforces the direction of travel on European defence spending.

Zelenskyy has returned a Polish state medal in an escalating row with Warsaw over second world war historical disputes. Poland is one of Ukraine’s most important military backers. If this deteriorates further it has implications for the cohesion of European support, though it reads more like political theatre for now.

On AI: Nobel laureate John Jumper, one of the architects of AlphaFold, is leaving Google DeepMind for Anthropic. He is not the only senior departure from DeepMind recently. This is a meaningful talent signal — Anthropic continues to pull top-tier researchers away from Google at a moment when the two are in direct competition for enterprise AI contracts.

The Met Office has expanded its extreme heat warning, with temperatures potentially reaching 36-37°C by Tuesday. An amber warning is coming into force. For UK businesses this is operationally relevant — infrastructure stress, reduced productivity, and potential transport disruption mid-week.

Starmer’s expected resignation statement is Monday. That is your event to watch in the next 48 hours.


Sources

Al Jazeera, Guardian, FT, BBC News, Politico, TechCrunch, Ars Technica — 2026-06-21